A survey on deep learning applied to medical images: from simple artificial neural networks to generative models.

Deep learning techniques, in particular generative models, have taken on great importance in medical image analysis. This paper surveys fundamental deep learning concepts related to medical image generation. It provides concise overviews of studies which use some of the latest state-of-the-art models from last years applied to medical images of different injured body areas or organs that have a disease associated with (e.g., brain tumor and COVID-19 lungs pneumonia). The motivation for this study is to offer a comprehensive overview of artificial neural networks (NNs) and deep generative models in medical imaging, so more groups and authors that are not familiar with deep learning take into consideration its use in medicine works. We review the use of generative models, such as generative adversarial networks and variational autoencoders, as techniques to achieve semantic segmentation, data augmentation, and better classification algorithms, among other purposes. In addition, a collection of widely used public medical datasets containing magnetic resonance (MR) images, computed tomography (CT) scans, and common pictures is presented. Finally, we feature a summary of the current state of generative models in medical image including key features, current challenges, and future research paths.

LDA filter: A Latent Dirichlet Allocation preprocess method for Weka.

This work presents an alternative method to represent documents based on LDA (Latent Dirichlet Allocation) and how it affects to classification algorithms, in comparison to common text representation. LDA assumes that each document deals with a set of predefined topics, which are distributions over an entire vocabulary. Our main objective is to use the probability of a document belonging to each topic to implement a new text representation model. This proposed technique is deployed as an extension of the Weka software as a new filter. To demonstrate its performance, the created filter is tested with different classifiers such as a Support Vector Machine (SVM), k-Nearest Neighbors (k-NN), and Naive Bayes in different documental corpora (OHSUMED, Reuters-21578, 20Newsgroup, Yahoo! Answers, YELP Polarity, and TREC Genomics 2015). Then, it is compared with the Bag of Words (BoW) representation technique. Results suggest that the application of our proposed filter achieves similar accuracy as BoW but greatly improves classification processing times.

Herniation of the left atrial appendage through a congenital partial pericardial defect.

We present a case of herniation of the left atrial appendage through a congenital partial absence of the pericardium. The diagnosis was demonstrated by echocardiography and the surgical correction achieved with autologous pericardium.

Embolization of the systemic arteries of the lung.

Embolization of the systemic arteries of the lung (described by Remy and colleagues in 1973) is now a useful method for the treatment of hemoptysis or hemorrhagic lesions of the lung prior to surgical treatment, or for local treatment of hemoptysis when surgery is contraindicated or unnecessary. The technique is based on the anatomy of the different divisions of the systemic circulation (bronchial and extrabronchial), which for various physiologic reasons may develop hypervascularization. The results, complications, and contraindications of systemic embolization have previously been described and the technique is now commonly practiced.

[Contribution of digital venous angiography to the evaluation of arterial hypertension. Cost evaluation]. / Apport de l'angiographie numérisée par voie veineuse dans le bilan de l'hypertension artérielle. Evaluation du coût.

Concerning 100 intravenous digital subtraction angiographies (IV DSA) performed for the study of arterial hypertension, the results are discussed according to two different achievements: diagnostic and economic. One hundred patients have been examined after the intravenous (IV) injection of contrast material, seventy times in peripheral and thirty times in central venous system. Out of 94 examinations that could be interpreted, 10 revealed stenosis of renal arteries higher than 50 per cent, one revealed fibromuscular dysplasia. IV DSA generally permits the correct study of renal arteries and compared to conventional angiography it gives only a small number of false negative results. However, the reliable study of intrarenal vascularisation can be obtained only by renal arteriography. The renal arteriography remains therefore necessary: when renal IV DSA gives insufficient data; to estimate the degree of stenosis in fibro-muscular dysplasia; to evaluate intrarenal vascularisation before renovascular surgery or angioplasty. To estimate the economic validity of renal IV DSA for the study of arterial hypertension, we have investigated: the actual cost of the examination for a department of radiology, compared with the cost of conventional examination; on the other hand, the influence of this examination on the duration of hospitalisation for evaluation of arterial hypertension. According to our investigation, this examination allows the average reduction of expenses for 180 F per patient with arterial hypertension, and shortens the time of hospitalisation for about one day. Owing to this diagnostic and economic contribution, renal IV DSA is becoming the first examination to be done for the evaluation of renovascular hypertension.

[Primary tumors of the diaphragm. Apropos of a case]. / Les tumeurs primitives du diaphragme. A propos d'un cas.

The diagnosis of diaphragmatic tumours is complicated by their rarity and because they are often difficult to distinguish from the more frequent tumours of surrounding structures. We describe two cases: an invasive fibroma and a primary hydatid cyst. We discuss the differential diagnosis of diaphragmatic tumours and suggest a systematic approach to their radiological diagnosis, stressing the value of ultrasonography, CT scanning and diagnostic pneumoperitoneum.

[Pulmonary hamartoma. Apropos of 49 surgically treated cases]. / Les hamartomes pulmonaires. A propos de quarante-neuf cas opérés.

A series of 49 patients with pulmonary hamartoma subjected to operation is described. 28 patients were male and 21 female, with a mean age of 49.8 years. Most cases were discovered on routine chest films. Six patients had radiologic changes produced by obstruction, while 43 had a rounded peripheral opacity. Fine calcifications were present in four cases. In no case was diagnosis achieved by bronchoscopy, whereas one of the more recent cases was diagnosed by percutaneous fine needle biopsy. Sinner has shown that this last technique can establish diagnosis in most cases. As such tumors are invariably benign and grow slowly, diagnosis by percutaneous biopsy renders operation unnecessary: periodic follow up only is required.

[Radiology of spontaneous pneumothorax in young patients. Apropos of 200 cases]. / La radiologie du pneumothorax spontané du sujet jeune. A propos de deux cents cas.

In 200 young patients with apparently idiopathic spontaneous pneumothorax, the following radiologic features were analyzed: degree of collapse on the initial chest film, areas of atelectasis, and presence of blebs, apical opacities, fibrous adhesions, pleural effusions, and controlateral shift of mediastinal structures. Confrontation of apical changes with pathologic findings in operative specimens suggests that mesothelial rupture with reactive hyperplasia results in a "pneumatization chamber" visible as a bullous image. Following drainage, homolateral shifts of mediastinum and four cases of pulmonary edema were recorded. Risk factors for pulmonary edema include severe pulmonary collapse with areas of atelectasis, persisting for more than 48 hours and an aspiration which either exceeded 1.5 l. of air or was performed with a depression of more than 30 cm of water.

[Emergency radiology in acute traumatic rupture of the thoracic aorta. Detection of atypical forms. Apropos of 52 cases]. / La radiologie d'urgence dans les ruptures traumatiques aiguës de l'aorte thoracique. Dépistage des formes atypiques. A propos de cinquante-deux observations.

Fifty-two traumatic ruptures of the thoracic aorta were hospitalized between 1972 and 1982, with 46 angiographies. The most significant clinical sign of aortic rupture is the difference in blood pressure between the upper and lower limbs. The frequency of chest film findings is discussed. The aortography by arterial route must be performed at the sligh test suspicion, sometimes without radiographic signs, to establish diagnostics and detect associated lesions (dissection) and unusual types (low localization, multiple localization, localized rupture of the intima.

[Broncholithiasis]. / La broncholithiase.

Eight cases of broncholithiasis requiring surgical treatment are reported, and diagnostic and therapeutic difficulties of this affection discussed. Clinical symptomatology is not very specific and associates slight or moderate hemoptyses with signs of a febrile pulmonary disorder. Expectoration of a broncholith was not observed in these cases. Radiological images were suggestive by demonstrating hilar and/or peripheral calcifications, often with a parenchymatous opacity in the same region. Fibroscopy is not always conclusive and may even suggest the presence of a tumor. A tuberculous etiology is admitted in France in spite of the absence of bacilli in the sputum. Differential diagnosis from cancer is a real problem, this explaining why two pneumonectomies were performed, in addition to the six lobectomies.